310 Mr. E. Schunck. 



formation into phyllocyanin is effected by the action of acid. Tbe 

 behaviour of phylloxanthin to concentrated sulphuric acid closely 

 resembles that just described. 



When cupric acetate is added to a solution of phylloxanthin in 

 boiling glacial acetic acid the solution becomes dark green, and a 

 compound is formed very similar to that which phyllocyanin yields 

 when treated in the same way. The solution, on cooling and stand- 

 ing, gives a dark-coloured deposit, which, after filtering off and treat- 

 ment with dilute hydrochloric acid, so as to remove any excess of 

 cupric acetate that may be present, is redissolved in boiling glacial 

 acetic acid. From this solution the compound crystallises out in 

 small scales, which are purple and lustrous by reflected light and 

 pale green by transmitted light. It closely resembles the corre- 

 sponding phyllocyanin compound ; its solutions show the same absorp- 

 tion spectrum as those of the latter, though they have less of a blue 

 tint, and appear more green. When the same experiment is made 

 using zinc acetate instead of cupric acetate no change of colour 

 takes place, and the acetic acid solution on cooling deposits unaltered 

 phylloxanthin ; in this respect the two substances show a marked dif- 

 ference, since phyllocyanin yields a double compound with zinc and 

 acetic acid, as described in Part I of this memoir. 



When ferrous oxide and argentic oxide are employed along with 

 phyiloxauthin and acetic acid compounds are formed similar to those 

 yielded by phyllocyanin, but their properties are not of sufficient 

 interest to merit detailed description. Towards lead acetate phyllo- 

 xanthin, like phyllocyanin, behaves with complete indifference. 



When metallic tin is added to a solution of phylloxanthin in con- 

 centrated hydrochloric acid the phenomena are similar to those 

 observed in the case of phyllocyanin. After standing some time the 

 bright bluish-green colour of the solution changes to olive, and it 

 r.ow gives with water a brown precipitate. On allowing the hydro- 

 chloric acid solution to stand in contact with metallic tin for some 

 time longer, it becomes red, and now gives with water a red floccu- 

 lent precipitate, which on being filtered off and washed turns brown, 

 and then dissolves in alcohol with a brown colour ; the alcoholic solu- 

 tion shows only a faint band in the green, but on the addition of a 

 little caustic alkali it turns yellow, and now shows three bands, 

 which are not, however, very distinct. 



Phylloxanthin does not dissolve readily in aqueous alkali, but it 

 does so with ease when alcoholic potash or soda is employed. When 

 treated with boiling alcohol to which a little alcoholic potash is 

 added phylloxanthin dissolves at once and entirely, yielding a red 

 solution, which on continuing to boil turns green. On standing for 

 some time the solution gives a dark-coloured deposit, which is 

 filtered off, washed with alcohol, and dissolved in water. The watery 



